Process of producing conical



Dec. 17, 1935. o UNDGREN PROCESS'OF PRODUCING CONICAL DISKS FOR CENTRIFUGAL SEPARATORS Original Filed Oct. 12, 1929 by?! In maw 7 W1 4% Jon/ q y UNITED STATES PATENT, OFFICE.

PROCESS OF PRODUCING CONICAL DISKS FOR CENTRIFUGAL SEPARATORS Hans Oloi Lindgren, Appelviken, Sweden, assignor to The De Laval Separator Company, New York, N. Y., a corporation of New Jersey Original No. 1,939,356, dated December 12, 1933, Serial No. 399,408, October 12', 1929. Applica tion for reissue September 12, 1934, Serial No. 743,778. In Germany November 3, 1928 8- Claims. (Cl. 113-52) Centrifugalseparator bowls, particularly of the material that the relation between the cream separators, are usually provided with a thickness of the conical portion, measured at series of superposed plates of frusto-conical right'angles to the generatrix of the cone, and shape, popularly called disks", which divide the the thickness of the original sheetiron is equal separating space of the bowl into thin strata and to or smaller than the sine of the half top angle 5 greatly promote efiicient and rapid separation. of the cone. Each of these disks or cones is usually provided By the hall top angle of the cone is meant with an outwardly extending peripheral flange that angle which is formed, in a vertical secat its wider end and an inwardly extending tlon taken through the axis of the conical 10 flange at its narrow end. Since one of the facmantle, between such axis and the wall of the 10 tors on which the skimming efficiency of a bowl conical body of the mantle.

depends is the division of the separating space In order to obtain the desired displacement of 'of the bowl into the largest practicable number material it is necessary that the sheet iron shall of layers, it is desirable to make the conical porhave a suitable hardness. In the spinning option or the disk as thin as possible so that the eration, the initial blank should have the shape 15 largest practicable number of disks may be 01' a flat' sheet of even thickness and should be placed within the bowl. On the other hand, the positioned at about right angles to the axis of the peripheral flanges should be as thick as is conspinning element. sistent with the maintenance of flanges oi. adja- I! the desired relation between the thickness of cent disks properly spaced apart, because the the conical mantle and that of the flanges shall 20 thicker the flanges, the stifierjand consequently be equal to the sine of the half top angle of the the stronger, the disks. It is, of course, possible cone, the semi-manufactured disk can be proto make the flanges thicker than the conical disk duced in a single operation. body because the body extends at a steep angle I! the desired relation between the thickness to its axis while the flanges extend at a wide 01' the conical mantle and that 01 the flanges g5 angle to the axis, normally, but not always, at a shall be less than the sine of the half top angle right angle thereto. of the cone, the spinning operation should be Heretofore the flrst stage of manufacture has such as to produce a semi-manufactured disk involved the production of disks with conical whose top angle is smaller than that of the body and flanges oi uniform thickness, the conifinished disk. The disks can then be shaped to 30 cal body being subsequently thinned to the deflnal form and finished by pressing or by the sired degree by turning or grinding. This methusual spinning. 0d of production is, however, open to serious. If the desired thickness of the outer flange objections. Such disks, ii of iron, are more ex is less than oi! the original material but greater posed to rust than disks which have not been than that of the conical mantle. I produce, by 35 worked with cutting tools; probably because the spinning, a semi-manufactured disk in the shape surface of the material is compressed in the rollof two conical mantles, one below the other, the ing operation and also because the original surtop angle of the lower mantle being made greater face is less contaminated than the interior by than that of the upper mantle. By bending up slag impurities and gas bubbles. Further, the .the lower mantle to form a flange, there is ob- 40 process is expensive, in that additional operatained a disk having a body of the desired retions, for example, the turning, are necessary, duced thickness, an inner flange having the same and that the loss of the considerable quantity of thickness as that oi! the original material. and material that is turned off is substantial and, an outer flange whose thickness is less than that especially in the production of disks oi non-reof the inner flange but greater than that of 45 sistant metal, quite serious. the conical body.

The present invention has for its object the In the production of disks of rustless metal, production, as heretofore, of a disk comprising it is possible to proceed as follows: A semia thin conical mantle and thicker flanges, by a manufactured disk in the shape of a frustum relatively simple and inexpensive process. It of a cone is produced by spinning. The upper involves the production of such disks from sheet part is bent to form the inner flange oi the disk. iron or other metal having. preferably, the same The outer flange is formed by bending up the thickness as the inner flange, and the employlower part oi. the cone to form a flange of twice ment. of a special spinning operation which the desired width and then bending this flange effects Such a reductmn in e thickness, upon itself (double-bending) to form a flange 55 oi twice the thickness of the conical body. By this procedure a still outer flange is obtained, since the material of the flange during the manufacture is also exposed'to cold-working so that the elastic limit of the material is considerably increased.

The several described mechanical manipulations constituting illustrative embodiments of my invention are shown in the accompanying drawing, in which:

Fig. 1 is a tie view of a disk blank, a die and clamp for holding the disk, and a spinning roller which cooperates with the die toshape the disk.

Fig. 2 is a view, similar to Fig. 1, showing the disk spun. to shape.

Figs. 3, 4 and 5 are diagrams showing modified manipulations embodying my invention Fig. 6 is a diagram showing the relation of the thickness of the conical body to that of the original blank.

In Fig. l a die 1: (shown broken away) having a conical periphery has clamped against its upper face a flat disk blank of uniform thickness.

A spinning roller g spins the blank into the shape shown in Fig. 2 by moving in a flxed path, indicated by the dotted lines in Figs. 1 and 2, pa.rallel to the surface of the conical die and at a distance therefrom equal to thethickness of the blank a multiplied by the sine of the half top angle of the conical portion to be formed. -In Fig. 2 the disk comprises an upper (inner) flange I) having the thickness of the original blank, a lower (outer) flange 0 having the thickness of the original blank, and airusto-conical body d whose thickness relative tothat of the original blankisequaltotheslneofthehalftopangle of the cone.

In Fig. 8 the disk is produced by the same operation, but the body is thinner than in Fig. 2. This greater thinness is produced by first forming a body e (shown in broken lines) whose top angle is smaller than that of the finished disk and then expanding the body into its ultimate shape as indicated at I.

InFlg.4 theupperpartof thediehasaperiphery inclined ata relatively small angle to its axis and the lower part of the die has a periphery inclined at a relatively large angle to the axis, so that, at the conclusion of the spinningoperationadiskbodyisformedhavingan upper frusto-conical part 0 extending at a relatively sharp angle to its axis and a lower frusto-,

conical part It extending at a relatively wide angle to such axis. The lower part It is of greater thickness than the upper part a and is bent up, as shown in broken lines, to form the lower (outer) flange. The lower part h, when bent out to form the lower flange, is of greater thickness than that of the body but of less thickness than as shown in Pig. 6, it may be readily seen'that a conewithhalftopangie kmadefromabiank with thickness ti will have a thickness t;=ti sine 1:.

The invention is not limited to the above described and illustrated embodiments, which illustrate several of numerous specific variations.

The terms "upper" or "inner" and. "lower" and outer are used, in their relative sense, for convenience only, and are in accordance with the positions that the disks have in the usual bowl rotatable on a vertical axis. It will be understood, however, that in the spinning operation the axis of the machine may be hori- 1o zontal, in which case the blank would not be clamped against the upper face of the die.

What I claim and desire to protect by Letters Patent is:

1. That process of, manufacturing centrifugal l6 separator disks having flat flanges and an intermediate frusto-conical body, which comprises forming a flat circular disk blank of approximately the same diameter as the flnished disk, placing it on a conical form and by rolling an intermediate zone, displacing the material therein axially only to form it into a frusto-conical surface.

2. That process of forming centrifugal separator disks having relatively thick fiat flanges and an intermediate relatively thin frusto-conical body, which comprises forming a flat circular disk blank of a diameter approximately the same as that of the finished disk and of a thickness equal to that desired in the modes, placing it on $0 a frusto-co'nical form and by rolling an intermediate zone in the blank displacing the material axially only to form said thin frusto-conical body leaving the inner and outer portions unchanged to form relatively thick flanges.

3. In the manufacture of separator disks having inner and outer flanges and a conical intermediate body, the process which comprises forming a flat circular disk blank of a diameter approximately equal to that of the finished disk and of a thickness substantially greater than the desired thickness of the conical intermediate body of the finished disk, placing the blank on a conical form, subjecting that intermediate portion of the blank extending from the desired outer diameter of the inner flange to the desired inner diameter of the outer flange to a spinning operation adapted to only axially displace said intermediate portion and thereby reshape it into a conical body having substantially the same minimum and maximum diameters as said in-' termediate portion of. the blank and simultaneously with such change in shape reduce the thickness of said intermediate portion so that it is equal to the thickness of the original blank multiplied by the sine of the half top angle of the conical portion.

4. In the manufacture of centrifugal separator disks having relatively thick inner and outer flanges and a relatively thin frusto-conical intermediate body, the process which comprises forming a flat circular disk blank of internal and external diameters approximately equal to that of the finished disk, placing it on a conical form, and subjecting only that intermediate part of the blank extending from the desired outer diameter of the inner flange to the desired inner diameter of the outer flange to a spinning operation adaptedtosoonlyaxiallydisplacethematerlal ofthe blank as to reduce the thickness of and so elongate and expand said intermediate part asto reshape it into a frustO-conicai body having substantially the same minimum and maximum diameters as said intermediate part of the blank, the resultant disk comprising a frusto-conical 76 body composed substantially solely of the metal of said intermediate portion and end flanges from or into which substantially no metal has been drawn or forced in the spinning operation.

5. The process of forming articles having a,

taper portion which comprises forming a flat circular blank of approximately the same diameter as the greatest diameter of the finished article, placing it on a conical form and by rolling a zone thereof displacing the material there in axially only to form it intoa frusto-conical taper portion.

6. The process of forming articles having a taper portion which comprises forming a flat circular blank of approximately the same diameter as the greatest diameter of the finished article, placing it on a form having the shape of the interior of the taper and by rolling a zone thereof displacing the material therein axially only to form it into taper portion.

7. The process of forming articles having a taper portion which comprises forming a flat I circular blank of approximately the same diameter as the greatest diameter of the finished article, placing it on a conical form and by rolling a zone thereof displacing the material therein axially only to form it into a frustoconical'taper portion having a thickness approxifnatelyequal to that of the original blank multiplied by the sine of one-half the top angle of the conical 7 portion.

8. The process of forming articles having a taper portion which comprises forming a flat circular blank of approximately the same diameter as the greatest diameter of the finished article, placing it on a form having the shape of the interior of the taper and by rolling a zone thereof displacing the material therein axially only to form it into taper portion having at each point thereof a thickness approximately equal to that of the original blank multiplied by the sine of one-half the inner angle of the taper at said point.

HANS OLOF LINDGREN. 

